Lubrication systems for sewing machines



A ril 21, 1959 w. J. EDWARDS 2,332,849

LUBRICATION SYSTEMS 'FOR SEWING MACHINES Filed Oct. 3, 1956 w ((l' 1 'IIIIIIIIIIIIIIIIIIIIIIIA III M \INVENTOR. F lg 3 William J. Edwards WITNESS I 3| n/mw%.. 5 W 6% A TTORNE Y 2,882,849 Patented Apr. 21, 1959 ice LUBRICATION SYSTEMS FOR SEWING MACHINES William J. Edwards, Nichols, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Application October 3, 1956, Serial No. 613,784

4 Claims. (Cl. 112-256) This invention relates to a system in a sewing machine for automatically supplying lubricant to bearing surfaces of the stitch forming mechanism, and more particularly to a lubrication system in a sewing machine which utilizes the normal motion of the moving parts of the machine to force lubricant in desired paths to the surfaces to be lubricated.

It is an object of this invention to provide a lubrication system for a sewing machine in which the normal motions of the moving parts of the machine serve to distribute lubricant in a positive manner to the bearing surfaces.

It is a further object of this invention to provide, in a sewing machine, a positively operating automatic lubrication system of the above character in which the parts are simple and economical in form and in relationship one with the others.

With the above and other objects and advantages of this invention in view as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

Fig. 1 illustrates a portion of the bracket-arm head of a sewing machine frame in vertical cross section exposing the needle-bar actuating mechanism carried within the bracket-arm head, portions of which are broken away and illustrated in cross section.

Fig. 2 represents a horizontal cross-sectional view of the bracket-arm head taken substantially along line 2-2 of Fig. 1 and illustrating portions of the needle-bar actuating mechanism in horizontal cross section.

-Fig. 3 represents a cross-sectional view of the needlebar driving crank member taken substantially along line 3-3 of Fig. 2.

Referring to the drawings, the sewing machine illustrated has a frame including a hollow vertical standard 11 from which extends a bracket-arm 12 which at its free extremity is formed with a hollow sewing head 13 closed by a sheet metal cover plate 14. An aperture 15 formed in the upper wall of the hollow standard is similarly closed by a cover plate 16.

Journaled in the bracket-arm 12 in spaced ball bearings 1717 is a tubular shaft 18. The ball bearings 17- 17 effectively divide the hollow machine frame into three compartments, i.e., a compartment in the standard 11, one in the bracket-arm 12 and one in the sewing head 13. The tubular shaft 18 extends at one extremity into the compartment in the hollow standard 11 and at the other extremity into the compartment defined in the hollow sewing head 13. Fixed to the shaft 18 within thestandard 11 by a pin 19 is a crank arm 29 formed with a pivot pin 21 which is embraced by the upper extremity of a driving pitman 22. The pitman 22 is arranged to impart oscillatory motion to the shaft 18. The US. Hale Patent No. 2,652,799, September 22, 1953, may be referred to for a disclosure of suitable driving connections by which the pitman 22 may be actuated to impart oscillation to the shaft 18. The Hale patent is also referred to for its disclosure of a lubricant splasher associated with the pitman whereby a lubricant mist may be maintained in the hollow standard during operation of the machine. This lubricant mist within the hollow standard constitutes a lubricant supply which the lubricating system of this invention draws upon in order to furnish oil to various bearing surfaces as will be described hereinbelow.

Disposed on the shaft 18 within the hollow sewing head 13 is a crank arm 23 formed with a crank pin 24 which is pivotally connected by a link 25 to a pivot stud 26 clamped by means of a split collar 27 and a clamp screw 28 to a needle-bar 29 journaled for endwise reciprocatory movement in bushings 3030 carried in the sewing head 13. The crank arm 23 is provided with a split collar embracing the shaft 18 and the crank arm is made fast to the shaft by a clamp screw 31.

The lubrication system of the present invention which is particularly adapted for supplying lubricant to the bearing surfaces between the needle-bar actuating crank pin 24 and the link 25 and those bearing surfaces between the link 25 and the pivot stud 26 on the needle-bar, comprises a bore 32 formed axially of the needle-bar actuating shaft 18. At the standard extremity of the shaft, the bore 32 terminates short of the end of the shaft and an axial bore 33 of considerably smaller diameter joins the bore 32 with the standard end of the shaft. At the opposite or sewing head extremity of the shaft, the bore 32 ,is formed with internal threads and fitted with a threaded metering plug 34 formed with a smooth cylindrical valve stem portion 35 adapted to cover a radial port 36 formed in the side wall of the bore 32 of the shaft 18. A lock nut 37 on the threaded metering plug 34 may be used to secure the metering plug in selected position of adjustment with respect to the port 36.

Cooperating with the radial port 36 for the purpose of providing a lubricant conducting passageway from the bore 32 of the shaft 18 to the bearing surfaces to be lubricated is a radial bore 38 formed in the crank arm 23 and disposed to open onto the radial port 36 when the crank arm is arranged properly on said shaft 18. The crank pin 24 is formed with an axial bore 39 which joins the bore 38 in the crank arm. The axial bore 39 in the crank pin is traversed by a radial bore 40 extending diametrically across the crank pin, and a plug 41 is fitted into the axial bore 39 between the radial bore 40 and the free extremity of the crank pin. A shallow annular groove 42 is formed in the crank pin 24 joining the extremities of the radial bore 40. The connecting link 25 is formed with a wick filled bore 43 extending lengthwise of the link and joining the annular groove 42 in the crank pin 24 with a radial bore 44 formed in the pivot stud 26. The pivot stud is also formed with an axial wick filled bore 45 which joins transversely the radial bore 44 formed therein.

Disposed within the bore 32 of the shaft 18 is a continuous length of wick 46 preferably in the form of a loop with the closed or folded extremity of the loop arranged to project through the smaller diameter bore 33 and into the space within the hollow standard. The free extremities of the loop of wicking extend within the shaft bore 32 to a point opposite the radial port 36. Arranged within the bore 32 with the wick 46 is a rod 47 which is loose within the shaft bore and is thus free to partake of movement relative to the shaft.

In operation, the folded extremity of the wick 46 extending beyond the shaft 18 and into the hollow standard 11 will come in contact with the lubricant mist sustained therein by the splasher on the pitman 22 as described in the above mentioned Hale Patent No. 2,652,799. A wick, as is known in the art, has a propensity for transporting a liquid along its length by a capillary action of the wick fibers. Lubricant Will thus be carried by the wick to within the bore 32. During operation of the sewing machine, the shaft 18 will be oscillated by the pitman 22 for the purpose of actuating the needle-bar 29. The loose rod 47 within the bore 32 will thus be shifted repeatedly into and out of contact with the free extremities of the wick 46 within the shaft bore. The consequent beating action of the rod 47 upon the wick 46 will serve to dislodge the lubricant from the wick. The lubricant which is deposited within the shaft bore 32 free of the wick 46 is prevented from returning to the hollow standard 11 because of the shaft bore 33 of reduced diameter. The lubricant thus freed from the wick 46 may pass, however, through the radial port 36 of the shaft, through the radial bore 38 of the crank arm, the bores 39 and 40 of the crank pin 24, and the wick-filled bore 43 of the connecting link 25 and thus find its way to the bearing surfacesbetween the crank pin 24, the pivot pin 26, and the connecting link 25.

With the construction of the present invention, lubricant is supplied to the bearing surfaces in a positive manner because the components coact to provide a pumping action to deliver the lubricant to the bearings. The combination of the capillary action of the wick which draws lubricant into the bore 32 and the beating action of the rod 47 which drives the lubricant from the wick and to the bearings provides a continuous flow of lubricant the rate of which may be regulated by the metering plug 34.

Having thus set forth the nature of this invention, what I claim herein is:

1. In a sewing machine having a frame, a tubular shaft journaled in said frame, actuating means operatively connected to said shaft for imparting oscillatory movements thereto, means operatively connected to said shaft and adapted to be driven thereby, said last named means including a bearing surface, means defining a lubricant conducting passageway between the interior of said tubular shaft and said bearing surface, a wick disposed within the bore of said tubular shaft, said wick being of normally smaller cross sectional size than the bore of said tubular shaft means for introducing lubricant into contact with said Wick, and a wick beating member arranged loosely within said tubular shaft for engagement with said wick.

2. In a sewing machine having a frame formed with atleast two compartments, a tubular shaft journaled in said frame and extending into each of said compartments, actuating means operatively connected to said shaft for imparting oscillatory movements thereto, means within a first of said compartments operatively connected to said shaft and adapted to be driven thereby, said last named means including a bearing surface, means defining a lubricant conducting passageway between the interior of said tubular shaft and said bearing surface, a wick extending from a point within said tubular shaft to a point outside of said shaft bore and within the second of said frame compartments, said wick being of normally smaller cross sectional size than the bore of said tubular shaft means within said second frame compartment for introducing lubricant into contact with said wick, and a wick beating member arranged loosely within said tubular shaft for engagement with said wick.

3. In a sewing machine having, a frame, a tubular shaft journaled in said frame, actuating means operatively connected to said shaft for imparting oscillatory movements thereto, means operatively connected to said shaft and adapted to be driven thereby, said last named means including a'bearing surface, means defining a lubricant conducting passageway between the interior of said tubular shaft and said bearing surface, means disposed Within one extremity of the bore of said tubular shaft to constrict the diameter ofsaidbore, a continuous wick extending from a point outside said shaft bore, through said shaft bore constricting means and into said shaft bore, said wick being of normally smaller cross. sectional size than the bore of said tubular shaft means. for introducing lubricant into contact with said wick-outside said shaft bore, a wick beating member arranged loosely within said tubular shaft for engagement with said wick, and an adjustable metering plug arranged in said passageway between the interior of said shaft bore and. said bearing surface.

4. In a sewing machine having a compartmented frame including a bracket-arm compartment and a standard compartment, a tubular shaft journaled in said frame and extending into each of said compartments, actuating means operatively connected to said shaft for imparting oscillating movements thereto, a needle bar actuating mechanism drivingly connected to said shaft within said bracket-arm compartment and including a bearing surface, means defining a lubricant conducting passageway between the interior of said tubular shaft and said hearing surface, a wick disposed lengthwise within said tubular shaft, means within said standard compartment-for introducing lubricant into contact with said wick, and: a wick beating rod arranged loosely within said tubular shaft in substantially parallel relation with said wick.

References Cited in the file of this patent UNITED STATES PATENTS 2,284,474 Peets et. a1. May 26, 1942 2,652,799 Hale Sept. 22, 1953 2,762,325 Hale et al. Sept. 11,1956 

